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R. MAGPARLANB. TUB ULAR WATER GRATE.

No. 488,170. Patented Deo.. 13, 18112.

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R, MACPARLANH TUBULAR WATER GRATE.

110.488,170. Patented Dec. 13, 1892.

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4UNITED STATES PATENT Orrics.

ROBERT MACFARLANE, OF MAGOG, CANADA.

TU BU LAR WATER-G RATE.

SPECIFICATION forming part of Letters Patent No. 488,170, dated December 13, 1892.

- Application filed September 12. 1891. Serial No.4:05y549- (N0 111011810 T0 all whom it may concerns Be it known that I, ROBERT MAGFARLANE, a subject of the Queen of Great Britain, and a resident of the town of Magog, Province of Quebec, Dominion of Canada, have invented a new and useful Improvement iii Tubular Vater-Grates, (patented in Canada, No. 37,059, dated July 24, 1891,) of which the following is a specication.

In using the finelygranulated cheaper grades of coal in the furnace of a steam-boiler an ordinary furnace-grate will soon become so clogged with clinkers as to render it useless until the clinkers are with great difliculty removed therefrom; and it is the object of my invention to prevent the formation of clinkei's upon the grate-bars when using coal of inferior qualit-y, thus securing greater economy in the cost of steam-power; and my invention consists in the employment of tubular grate-bars of such proper dimension and nearness to each other as to obtain the economical combustion of the said coal, and having the grate-tubes connected at their ends by return-bends, so as to provide acontinuous passage for a stream of water which, entering at one side and passing rapidly through all the tubes and bends, will flow out' at the opposite side either to other use or to Waste after thus serving to reduce the temperature of the grate-bars, so that the clinker will not attach itself thereto or to be conducted to the boiler to feed the same with hot Water, as desired.

Figure l represents a plan View of my iin-a proved non-clinckering tubular grate. Fig. 2 represents an enlarged detail section showing two adjacent grate-bars and the returnbends for connecting the same. Fig. 3 represents an elevation of the front of the boiler-a furnace and a section of the grate.

In the accompanying drawings, A repre sents the ashpit; B B, the walls of an ordinary furnace; C, the boiler, and D the trussbar supporting the tubes of the grate. The feed-pipe E is connected with the boiler C at the pipe O, and is provided with a stop-cock P, and to the pipe E, below the stop-cock P, is attached the branch pipe F, which is provided with the stop-cock G and the check-valve H, and is connected with the upper tube I of the side grate J, as shown in Fig. 2, the check- Patented in Canada July 24, 1891. No. 37,059.

valve H serving to prevent back -pressure from the said grate. After entering the tube I the water is forced through the said tube to the rear end where a return-bend acarries it to the underlying tube I of the side grate, thence returning through the said tube to the return-bend a', by means of which it is carried into the irst tube I2 of the bottom grate J', and in a like manner through each s ucceeding horizontal tube of the grate J', flowing backward in one tube and forward in the next, until finally passing out of the upper tube l3 of the side grate J 2 at the opposite side of the furnace and into the waste-pipe K. The waste-pipe K is provided with a stop-cock L, by the closing of which and the opening of the stop-cock M in the pipe N, the water which has become heated in its passage through the grate, may be conveyed upward through the pipe N and enter the boiler through the pipe O, the pipe N being also provided with a check-valve R.

The cold feed-water for the grate which is first brought in at the top of the side grate J will become somewhat warmed before reaching the tubes of the bottom grate J so that the low temperature of the grate J will not be sufcient to retard the proper combustion of the fuel.

In their normal positions the stop-cock P will be closed, and the stop-cocks G and M open, so that the heated water from the grate will flow into the boiler, and the stop-cock L in the waste-pipe K may be either closed for turning all the water into the boiler, or partially open in order to allow a stronger iiow of water through the tubes of the grate to keep them from becoming overheated, thereby preventing the formation of clinker thereon, and the proportion of the water passing through the grate-tubes that is from time to time required in the boiler is directed thereto by the proper adjustment of the stop-cocks L and M. By closing the stop-cock G and opening the stop-cock P the feed-water will be diverted from the grate and carried to the boiler in the ordinary way whenever desired for any purpose. The tubes I, forming the grate, are connected to return-bends a by means of right and left hand screw-threads d d', cut on the opposite ends of the tubes, so that by turning them in one direction both ICO ends of the tube will screwinto the respective return-bends, and by turning in the opposite direction will screw out and become free therefrom, thus providing for the removal and replacement of a defective tube; and sufficient space is to 'be left between the back wall B of the furnace and the return-bends to allow for the backward movement of one portion of the grate to facilitate the taking out or putting 1n of any tube required; and by the employment of the return-bends having right and left hand screw-threads, so that the tubes can be arranged close to each other, I am enabled to form a complete practical grate capable of burning the cheaper and lower grades of fine coal, and at the same time avoid the obstructive formation of clinkers, which would occur in the attempt to burn this class of fuel upon an ordinary grate.

It will be understood that it is important that the supply-pipe for furnishing the water for the grate should be of sufficient size and be worked under such pressure as to provide an abundant supply of water to reduce and regulate the temperature of the grate so that the clinker will not form thereon.

A lthough the arrangement of tubes composing the grate and connecting pipes, herein shown, is thought to be the best application of my invention, 'yet I do not confine myself to the particular mode of construction.

In some cases I force the feed-watersimultaneously through the pipe E and through the grate J and pipe N, both currents meetlng at the common pipe O to enter the boiler, and by this means any desired proportion of the feed-water may be passed through the grate'by the proper adjustment of the respective stop-cocks, a desired proportion of the water lpassing to the boiler through the grate J and pipe N, and the remaining portion through the pipe E, both streams passing into the boiler through the pipe O.

I claim as my inventionl. The combination, with the inlet-pipe F, provided with the stop-cock G and check-valve I-I, and the tubular grates J J J2, connected with the pipe F, of the waste-pi pe K, provided with the stop-cock L, the pipe N, provided with the stop-cock M and check-valve R, and the connected boiler C, substantially as described.

2. The combination, with the boiler C, of the feed-pipe E, provided with the stop-cock P and communicating with the boiler through the pipe O, the branch pipe F, provided with the stop-cock G and check-valve H, the tubular grate J, the waste-pipe K, provided with the stop-cock L, the pipe N, provided with the stop-cock M and check-valve R, and also connecting with the boiler through the pipe O, substantially as described.

3. The combination, with the boiler C, of the pipe O, connected therewith, the feed-pipe E, connected with the pipe O and provided with the stop-cock P, the tubular-grate J connected with the pipe E, and the pipe N, connected with the tubular grate J and with ythe pipe O, and provided with the stop-cock M to form a circuit with the pipe E, substantially as described.

hl ROBERT s MACFARLANE.

mark

Witnesses THOMAS BELL, J. I. GANVIN. 

